This research aims at a detailed description of how the eye communicates with the brain. We want to understand the precise rules by which the action potentials of optic nerve fibers encode the visual stimulus presented to the eye, and how these rules are implemented by the neural circuitry of the retina. This will be achieved through a combination of methods: Multi-electrode array recording allows us to monitor in parallel the visual responses of many retinal ganglion cells in the isolated retinae of salamander and rabbit. Simultaneously, we will access individual interneurons with an intracellular microelectrode; recording and stimulation of that cell will reveal its role in visual processing pathways. Finally, mathematical models of retinal light responses will integrate these observations into an overall understanding of circuit function. The specific aims are: (1) to understand the circuit mechanisms that produce synchronous firing among retinal ganglion cells; (2) to investigate the effect of fixational eye movements on retinal processing, and the function of ganglion cells selective for differential motion; (3) to determine how the retina adapts to the statistics of the visual environment, and whether it performs a generalized form of novelty detection; (4) to construct mathematical models of retinal processing that can accurately predict ganglion cell firing from an arbitrary visual stimulus. Results from this work will lead to a better understanding of vision, and how the retina contributes to the overall process. They may also aid in future therapies, such as a retinal prosthesis that emulates the function of neural circuits in the retina. [unreadable] [unreadable]